Dashpot



Patented.. June 16, 1931 UNITED STATES PATENT oiFFlicE LERNA ID."WALIDEN', OF KANSAS-CITY, KANSAS DASHPOT Application filed VJane/1:,

My invention relates to shock absorbers and more particularly to dashpots such as applied to weighing apparatus, or the like, the principal`objects being to hasten the stabilization Vof weighing apparatus andreduce the time necessary for ascertaining the weight after an articlehas been placed on the scales. Further objects are tol checkthe plungerof a vdash pot device at the beginning and end of each stroke,.topermitV relatively free move- Vment of the plunger over the greaterportion` of the path, and to assure the repose of the plunger at thesuitable position for correct;

Y of operative members of thel device kshown ig.`3`is across section ofthe device on the line 3 3, Fig. 1.V Y Fig. 4 isa section on the line4-4, Fig.l l. n VReferring in detail to the drawings:

1 designates :a vdash poty adaptedl for sup;

port in lixed relation with weighing apparatus not shown, and comprisingaV fluid-containing `cylinder' 2'having an enlargedupper end 3constitutinga rim'and producing a shoulder 4, and a cap or coverk 5screw-threadedlyengaged withthe rim. VA splash disk 6 provided withapertures 7 is supported by theshoulder 4. Y Y

A piston rod8 is adapted to be connected to a movable member-S) such asa stem4 of a weighing apparatus by a coupling '10, and

locked againstrotationby a nut y11, the rodl extending into the cylinderand having .a piston disk 12 fixed toits lowerp'ortronad] acent itslowerlend.` The pistonl disk 17s @provided 192s. Serial No. 282,587.; i

with radially spaced series `of yports 13, 14 and 15, and the movementof liquid through thelpots is controlled by means presently descri e Y Asleeve-like tubular valve support 16 eX` 50V tends slidably over theintermediate portion of the piston rod and through an opening 17 in thesplash plate and an openinglS in the cap, the edges of which arereenforced by an annular guide flange19. 55 Slidable lon the lower endof the rod 8 and .supported against the end of the sleeve 16 by a spring20 isa valve 21 comprising a flat ring extending radially su'iciently tocover the inL i vner group of ports 15 in the diskf12, the outer 60 edgeof the ring being spaced yinwardly from the ports 14. Y

Slidably mounted on the sleevel adjacent the lower end thereof is anannular valve 22comprising an annulus 23 adapted to overlie thel 65,

outer ring of ports 13, and a spider'24 comprising arms 25 extendinginwardly and angularly from the annulus and a bar portion 26 having anopening 27 axial of the annulus for `'mounting the valve on thesleeve.

Nuts 28 engaged ywith a threaded portion 29 of the sleeve retain aspring 30 coiled thereon and bearing against the spider of the l valve,whereby the sleeve .is urged upwardly over the rod, the valve beingsupported norymally by the piston disk. The support of the sleeve fromthe valve 21 and piston disk spaces the valve 21 from the ports 15, andthe spacing is regulated by `provision of a manu-L ally operable stopnut: 31 threaded konA a '805 threaded portion 32 of the rod exterior tothe cylinder, which engages the upper end of the sleeve. Y.

An annular valve 33 similar to the valve 22 is slidably mounted on therod in opposite 85 position from that of the valve 22,`and on theopposite side ofthe piston disk, and adapted to control the ports 14,the edges being spaced from the adjacent ports 13 and 15. The valve 33is normally urged into engagementv with 90k the piston disk to close theports 14 by a spring 34 coiled on the rod and anchored by nuts 35movably ixed to the rod adjacent its end.

The angularly extending arms of the spider of the valve 22 provides forrelative movements of the piston disk, valve 22 and valve 21, andparticularly for movement ot the valve 22 on the axis ot the valve 2l.The angularly extending spider arms olf the slidin valves 22 and 33further particularly provi e for avoidance of closing ot a port in agroup within the annulus comprising a valve,

In the illustrated use of the device, the cylinder is provided with asuitable fluid and fixed in relation to the device towhich it is to beapplied, for example a scale and secured to the scale base, and the rodis connected' to a movable member ot the device, for example the stem ofthe scale. lilovement ot the stem upon applying an article to be weighedcauses the rod to move downwardlyT in the cylinder, carrying the sleevewith it, the speed of movement being retarded by the relatively small.

v area of the ports l5, and proportionately to the adjusted spacing ofthe valve Q l 'trom said orts.

As the piston moves through the liquid, the pressure of liquid throughthe ports 13 moves soi the valve 22 away from the ports against theresistance of the spring 30, .vhereby tion is diminished, and thepister. and ster. `are permitted to move more rapidly. lVhen the pistonapproaches the end or' its travel, and the stem nears the position torinchcating weight, the pressure oit liquid is diminished, the spring 30moves the valve to close the ports 13, and retardation is increased. Theclosing of the ports 13 checks the movement of the stem to preventtheweig it-indieating parts from moving beyond the position for correctindication ot the weight.

When the article to be 'fzhed removed, the return movement ot the l.ision retarded initially byreason of the relatively small arca of theports l5 through which the liquid n'iay move, and pressure of liquidthrough the ports 14 moves the valve 33 away from said ports to increasethe area for passage ott liquid, for increasing the rate at which thepiston may return toward original position. The spring 34 tends torestore the valve to port-closing position as the piston nears thel endof its upward travel, to bring about en increased retarding effect atthe end oi' the stroke. The moving member therefore will come. to restnormally in weight-indicating position and a member connected therewith,such as a weight-indioating member, will not move beyond the zero pointoi' the scale.

What I claim and desire to secure by Letters Patent is:

1. A dashpot comprising a liquid-containing cylinder, a piston movablein the cylinder and provided with a plurality ot ports,

Lampes a sleeve extending in the cylinder, a piston rod in the sleeveand attached thereto, and spring-pressed means operable against oppositesides of the piston respectively controlling said ports.

2. A dash pot comprising a liquid-containing cylinder, a piston providedwith a plurality ot ports, a piston rod, a sleeve slidable on the rod,and spring-pressed means slidable on the sleeve and the rod torrespectively controlling said ports.

3. A dash pot comprising a liquid-containing cylinder, a piston providedwith a plurality of ports, a piston rod, a sleeve slidable on the rod,spring-pressed means slidable on the sleeve and the rod for respectivelycontrolling said ports, and means for adjusting the tension of thesprings. y

4. A dash pot comprising a liquid-containing cylinder, a piston having aplurality of ports, a piston rod, a sleeve slidable on thel rod, havingaA valve at its lower end conf trolling one of said ports,spring-pressed means slidable on the sleeve for controlling another ot'said ports, and spring- .iressed means slidable on the rod forcontrolling another of said ports.

5. A dash pot comprising a liquid-containing cylinder, a piston havinga. plurality ci ports, a piston rod, a sleeve slidable on the rod, a vlve at the lower end of the sleeve and slidable on the rod forcontrolling one ot said ports, spring-pressed means slidable on thesleeve for controlling another or" said ports, and spring pressed meansslidable on the rod for controlling another of said ports.

6. In a dash pot, a liquid-containing cylinder, a tubular valve supportslidably supported for reciprocation in the cylinder, a rod adapted forconnection with a movable member of the device to which the dash poi: isapplied and slidable in the tubular support, a. disk securedto the rodand provided with ports, a plurality ot valves on the supportcontrolling selected ports, and a valve slidable on the rod below thedisk controlling a selected port therein.

7. In a dash pot, a fixed liquid-containing cylinder having a cover, atubular alve support slidable in the cover and provided with a pluralityof valves, a rod adapted forV connection with a movable scale member andslidable in the tubular support, adisk fixed to the rod below thetubular support and pro- I vided with a plurality ot seriesv of ports,and

a valve slidable on the rod below the disk, said support'valves and rodvalve controlling selected series of ports.

8. In a dash potdevice of the character described, a` cylinder adapted.tor iixed support in relation to a scale, a rod fixed to a movablemember of the scale and extending into the cylinder,y a sleeve on therod having a flat set valve at its lower end, a valve slidable on thesleeve, a valve slidable on the rod, a disk fixed on the rod above saidlast Y named-valve and provided .with ports `respectively controlled bysaid rod valve and with ports controlled by the slidable valve onl `thesleeve, Vand means urging said'valves toward the disk.

9.y In a dash pot device of the character described, a cylinder adaptedfor iixed support inrelationto a scale, a rod iixed to a movable memberof the scale andextending into the spectively controlled by` said rodvalve and with`V ports controlled by the slidablev valve on the sleeve,and means urging said annular valves toward the disk. y

10. In a dash pot device' of the character' described, acylindervadapted for fixed supy port relation to a. scale, a rod iixedto a movable member of the scale and extending into the cylinder,a'sleeve on the rod having a valve at its lower end, a valve slidable onthe sleeve, a valve slidable on the rod, a disk `iixed on the rod abovesaid valve and provided with ports controlled by said valves and withports controlled by the valve on the sleeve, means urging said valvestoward the disk, and means. for adjusting the spacingV of said valvefrom the Vdisk for controlling movement of liquid through said selectedports. f

1l. In a dash pot device of the character described, a liquid-containingcylinder adaptedfor xed support, a rod adapted 'for attachment to a.scaley member and extending int-o the cylinder, a sleeve slidable on therod, a disk iixed to the rod below the end of the sleeve andr providedwith a plurality of annular series of ports, and a plurality of annularvalves controllingthe respective ports and independently movable underpressure of liquid produced by reciprocation of the rod.

l2. In a dash pot including a liquid containing cylinder, a piston inthel cylinder Yhaving a plurality of ports, and apiston rod,

a' sleeve on the Y rod, and spring-pressed means related respectively tothe sleeve and the rod andoperable against opposite sides of the pistonrespectively controlling said ports.'

13.111 va dash pot of the character `described, a liquidcontainingcylindena sleeve exten ding in the cylinder, a piston rod inthe sleeve', a pistonv provided with a plurality of ports, Valvesoperable against opposite sides or" the piston for controlling selectedports, and a pluralityy of` tensioning meansl anchored respectively tothe sleeve andthe rod for urging theV valves toward the piston tocontrol said selected ports. f

14. In a dashlpot device of the character described, `a `cylinderadapted ,for fixed sup.-

port in.L relation toa scale,- a rod member,a sleeve member on the rodand slidable in relation thereto,means for locking the sleeve to therod, one of said members being adaptu ed to be fixed/,to a movablemember of the scale, a piston provided-with aplurality oi' A' ports,andspring-pressed means for control-A4 ling selectedports. Y

15. In a dash pot including a liquid containing cylinder, a piston inthe cylinder having aiplurality of ports, spring-pressed meanscontrolling one of the ports from one side ofthe piston, a secondspring-pressed meansv controlling another port from the op-y posite sideofthe piston and manually operable screwthreaded means for varying theeiiective area of another port.

16. In a dash potoithe character described including a cylindera sleeveextending slidably in the cylinder, a piston rod extending through thesleeve and adjustably fixed thereto, and afvalve fmed to the sleeve, aypiston provided with a plurality oradially spaced annular series ofports, said valve controlling the inner series of ports,

and spring-pressed means for controlling the other ports;

l?. In a dash pot of the kcharacter described includinga-cylinder, asleeve extending slidably in the cylinder, a piston rod ex:- tendingthrough the sleeve and adj ustably iixed thereto and a valve fixed tothe sleeve, a pistonprovidedwth a plurality of ports including a portspaced Vinwardly from the other ports, said valve controlling said innerport, and spring-pressed means operating,

against opposite sides of the trolling the outer ports.

1S.` In a dash pot including a liquid-containing, cylinder and anapertured piston slidable in the cylinder, asleeve member ex-k tendinginto the cylinder, a rod member in piston for conthe-sleeve, one of saidmembers being secured .f

to the piston, means including a valve on one of said members and aspring-pressed valve .for controlling iow of ,liquidV through thepiston, and screwthreaded means for adjusting one kof said valves. y j

19. A dash pot including a liquid containthe cylinder, a rod member inthe sleeve, said members being adjustable with reference to each otherand one of said members being justment of said members for limiting flowof liquid through the piston, a. spring pressed valve for controlling`flow of liquid through the piston, and means for effecting adjustmentof said members.

20. A dash pot including a liquid contain- 116 y ing cylinder, anaperturedpiston slidable in the cylinder, a sleeve member extending intol12E; xed'to the piston, a valve responsive to ad- A ing cylinder, anapertured piston movable in Y the cylinder, means for respectivelylimiting and controlling flow of liquid through the piston including apair of members adjusta/ble with reference to each other, one of saidmembers being provided with a valve operable against; one side of thepiston, one of said members being fixed to the piston, a spring-pressedvalve operable against the other side of the piston, and mea-ns :foradjusting said members with reference to each other for regulating saidflow-limiting valve.

f In testimony whereof I affix my signature.

LER-NA D. WALDEN.

